Update docs

Author: gsusanto-fastly

doc/GUIDE.md

@@ -46,6 +46,8 @@ libfsm provides stable, “first-class” code generation for:
 
 ## Workflow Overview
 
+libfsm provides two main tools: **`re`** takes patterns from command line, **`rx`** takes patterns from file.
+
 ### 1. Validate the Regex
 
 Test behavior using any PCRE-compatible tool (e.g., [https://regex101.com/](https://regex101.com/)).
@@ -68,28 +70,34 @@ If unsupported constructs exist, libfsm reports the failing location.
 re -p -r pcre -l rust -k str '^item-[A-Z]{3}$' > item_detector.rs
 ```
 
-### 4. For Multiple Patterns
+### 4. Multiple Patterns
 
 ```bash
+# re - patterns from command line:
+re -p -r pcre -l go -k str '^x?a b+c$' '^x*def?$' '^x$'
+
+# rx - patterns from file:
 rx -p -r pcre -l vmc -k str -d skipped.txt patterns.txt > detectors.c
 ```
 
-* Combines all patterns into one function (like using `|` to join them)
-* Unsupported patterns are written to `skipped.txt`
+Both tools:
+* Combine all patterns into one function (like using `|` to join them)
+* Return `(bool, int)` - match status and pattern ID
+* Pattern ID is argument position for `re`, line number for `rx`
+* When encountering unsupported patterns: `rx` skips them to `-d` file and generates code with working patterns; `re` fails completely
 
 ---
 
-### `re` / `rx` Flag Reference
-
-| Flag | Purpose                     | Common Options                            | Notes                                      |
-| ---- | --------------------------- | ----------------------------------------- | ------------------------------------------ |
-| `-r` | Select regex dialect        | `pcre`, `literal`, `glob`, `native`, `sql`| `pcre` supports the widest set of features |
-| `-l` | Choose output language      | `go`, `rust`, `vmc`, `llvm`, `wasm`       | Use `vmc` for generating `C` code          |
-| `-k` | Generated function I/O API  | `str`, `getc`, `pair`                     | `str` takes string/slice, `getc` uses callback for streaming, `pair` takes byte array |
-| `-p` | Production mode             | *(no value)*                              | Generates optimized code                   |
-| `-d` | Output unsupported patterns | filename                                  | Only applies to `rx` (batch mode)          |
+### Flag Reference
+| Flag | Purpose                     | Common Options                             | Notes                                      |
+| ---- | --------------------------- | ------------------------------------------ | ------------------------------------------ |
+| `-r` | Select regex dialect        | `pcre`, `literal`, `glob`, `native`, `sql` | `pcre` supports the widest set of features |
+| `-l` | Choose output language      | `go`, `rust`, `vmc`, `llvm`, `wasm`, `dot` | Use `vmc` for `C` code, pipe `dot` into `idot` for visualization |
+| `-k` | Generated function I/O API  | `str`, `getc`, `pair`                      | `str` takes string, `pair` takes byte array, `getc` uses callback for streaming |
+| `-p` | Production mode             | *(no value)*                               | Generates optimized code                   |
+| `-d` | Output unsupported patterns | filename                                   | Only applies to `rx` (batch mode)          |
 
-For more detailed information on flags, see [include/fsm/options.h](../include/fsm/options.h).
+For more detailed information on flags, see [include/fsm/options.h](../include/fsm/options.h) and the man pages (by running `build/man/re.1/re.1` after `bmake doc`).
 
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